Earlier this year I walked along Pushkin Boulevard, which runs through the heart of the Eastern Ukrainian city of Donetsk.

Even back then the barricades had gone up and pro-Russian separatists had taken over the main municipal building that sits at one end of this picturesque avenue lined with trees and cafes sitting under their shade. The atmosphere was tense and men with guns and masks were the order of the day.

Barely 90 minutes' drive away in the town of Sloviansk those separatists with guns were already ratcheting up the violence that would become commonplace in the months that followed.

Despite this, it would have been near impossible to imagine the fate that would subsequently engulf this region.

Over the last few days there was yet another grim reminder of how Donetsk has been turned into a frontline city when two teenagers died and four were wounded when an artillery shell hit a school sports field as they played football.

The shelling was in the vicinity of Donetsk Airport, through which I transited in April but is now the focus of the fiercest fighting as separatists lay siege to Ukrainian forces holed up inside for the past five months.

The latest civilian deaths came a day after a separatist leader was sworn in as head of a self-proclaimed 'people's republic' in Donetsk, and both sides in the Ukrainian conflict accused each other of tearing up a peace deal and breaching a ceasefire officially in place since September 5.

Perhaps the most remarkable thing about the Ukraine conflict is the way it trundles on seemingly unnoticed here in the West and intervention remains at a minimum.

This apparent political impotence by the European Union in particular is epitomised by what critics say has been little more than a litany of diplomatic platitudes and expressions of "grave concern" at the extent of Russian interference and land grabbing in the region.

In Kiev, the frustration resulting from this is poignantly revealed in a new book by Andrew Wilson, Senior Policy Fellow at the European Council On Foreign Relations and a respected commentator on the region.

Entitled Ukraine Crisis: What It Means For The West, Mr Wilson tells of how at one stage vendors in Kiev were selling T-shirts to disillusioned Europhiles with the slogan: "F*** your grave concern".

It may come as something of a surprise to hear that more than 4,000 people have now been killed in Ukraine's conflict since pro-Russia separatist rebellions broke out in the industrialised east following the overthrow of the country's Moscow-backed leader Viktor Yanukovich in February.

Just as it was difficult at the beginning of the year to imagine where all this would lead, so, today, it remains problematic in predicting how events will play out long term in Eastern Ukraine.

In the most immediate terms, things do not look good. Only a few days ago Ukrainian President Petro Poroshenko ordered his military forces to reinforce several towns, including the port city of Mariupol and the city of Kharkiv, in case separatists mount a new offensive.

Certainly, witnesses on the ground this past week have reported an escalation in the flow of reinforcements, supplies and weapons from Russia across the border into eastern Ukraine.

Many of the reports depict convoys of Kamaz trucks carrying items such as Grad multiple rocket launch systems, ammunition and anti-aircraft weapons. Fuel trucks and armoured vehicles have also been sighted, as well as tank columns moving west by rail from Rostov-on-Don, Russia. Most of these sightings took place near Donetsk.

This is nothing new, but why now for this latest uptick in Moscow's military largesse?

One of the main reasons for choosing this moment to move more weapons and supplies into the separatist-held regions is that winter is fast approaching.

Doubtless, Kremlin military planners want to ensure their proxies have enough weapons, fuel and supplies to last through the winter months, when logistics throughout the region become more difficult.

Another key reason, according to the independent US-based intelligence monitoring group Stratfor, is the Kremlin's need to consolidate its gains in eastern Ukraine and stabilise its lines.

Finally, the increase in supply and weapons flows may suggest Russia is preparing for a build-up inside the rebel-held areas in preparation for an expanded military operation to gain new territories.

Nothing, however, about Moscow's motives is certain and all this movement has inevitably led many intelligence analysts to ponder the precise nature of Moscow's shifting strategy or intent.

One senior military official who is in little doubt about Moscow's aims is US Air Force General Philip Breedlove, who also runs the military's European Command. "Clearly we see one border that remains porous and enables a dense cooperation, training and equipping of Russian-backed forces in eastern Ukraine," General Breedlove was quoted recently as saying while talking about the current Russian-Ukraine boundary.

According to General Breedlove's assessment, what is happening is effectively a carbon copy of the scenario that unfolded in Crimea after Russian forces invaded and annexed the Ukrainian territory there earlier this year.

Russian President Vladimir Putin is, in effect, redrawing borders to help create "a situation that could develop into a frozen conflict" between Moscow and the Western-backed Ukrainian government in Kiev.

Perhaps what was most fascinating about General Breedlove's remarks during his recent Pentagon press conference was his candid admission there was little the Nato alliance could do militarily to stop Russia's steady incursion into Ukraine.

Nato, it seems, is way too busy reassessing years of tactical decisions that were based on the premise of Russia becoming a friendlier nation after the fall of the Soviet Union.

General Breedlove's take that Moscow is seeking to create a "frozen conflict" rather than expand its grip on territory is also borne out by the challenges Russia faces at home.

Polls indicate there is little appetite among ordinary Russians for a direct intervention in Ukraine.

Then there is the question of falling oil prices and a plummeting rouble that are giving Russian policy makers the jitters and leaving the public worried about the government's ability to finance its defence and energy projects while still meeting its social spending obligations.

To top all this off, while Nato, the EU and other bodies seem largely powerless to thwart Moscow's ambitions in Ukraine, the West does still remain more than capable of imposing damaging sanctions that would further aggravate the domestic political scene inside Russia.

For the moment then, Russia has no intention of taking over Ukraine. It will more than happily settle for what many suspect has always been its ultimate goal of preventing Ukraine from integrating with the West, especially Nato, and to turn the country into a neutral buffer state.

It will be a long, cold and bitter standoff in places like Donetsk this winter.